Billy Byrne is a low class American born in Chicago's ghetto. He grows up a thief and a mugger. "Billy was a mucker, a hoodlum, a gangster, a thug, a tough." He is not chivalrous nor kind, and has only meager ethics - never giving evidence against a friend or leaving someone behind. He chooses a life of robbery and violence, disrespecting those who work for a living. He has a deep hatred for wealthy society. He trains as a prizefighter but can not stop drinking. When falsely accused of murder, he flees to San Francisco and is shanghaied aboard a ship. Ironically, enforced sobriety, brutal ship's discipline and productive work improves him. The ship's secret mission is soon enacted - the hijacking of a specific yacht to take a millionaire's daughter, Barbara Harding, for ransom. Originally two stories, The Mucker begun in August 1913 and published by All-Story Weekly in October and November 1914; and The Return of the Mucker begun in January 1916 and published by All-Story Weekly in June and July 1916. The book version was first published by A. C. McClurg on 31 October 1921. From January 1922 to August 1939, Methuen (UK) published a version of The Return of the Mucker under the title The Man Without A Soul.